Flood Facts

FLOODPLAIN BOUNDARIES - Most of Roseville is “high and dry” as less than 7% of the City is within a floodplain, and most of the floodplain property is open space (no homes). The Engineering Division has the floodplain boundaries mapped.

CURRENT REQUIREMENTS - Building or filling within the 100-year floodplain is prohibited except in the Infill (central) area of the City and only if no impact is demonstrated. In all cases, the floor elevation of any structure is required to be at least two feet above the “future” 100-year floodplain's water surface elevation. “Future” means the drainage shed is assumed to be built out to the year 2040.

FLOODED STRUCTURES - In 1986, 209 structures incurred flooding. In 1995, 358 structures incurred flooding. There was more intense rainfall in 1995 than in 1986. Most homes that have incurred flooding were constructed prior to floodplains being mapped. No structures in Roseville built since 1980 have incurred flooding.

ALERT SYSTEM - After the ‘86 flood, we installed an alert warning system with 18 rain gauges, 19 stream level gauges, and a computer monitoring system. During high stream flows, we broadcast stream levels on Roseville Cable TV Channel 14/73. We also monitor Doppler radar and satellite imaging of incoming storms to assist us in advance notification efforts in the event evacuation of flood-prone areas is deemed necessary. The Fire Department uses a telephone auto-dialer system that notifies occupants as to the status of creek levels. In summer 2001, we put real-time stream gauge data on the City’s website. Installation cost of ALERT system = $625,000. Annual cost to maintain = $150,000.

ANNUAL STREAMBED MAINTENANCE PROGRAM - After the ‘86 flood, we entered into a Memorandum of Understanding with the State Department of Fish & Game to allow us to clear creeks of fallen trees and debris which could otherwise float downstream and block culverts and bridges. Annual cost = $100,000.

PLACER COUNTY FLOOD CONTROL DISTRICT - In 1989 we participated in creating the District. The District generated the Dry Creek Watershed Flood Control Plan that includes regional detention basins and other improvements within the Dry Creek basin. The District adopted a developer-paid fee to help fund these improvements. The District established improvement standards for development, and reviews development proposals. Up front cost = $300,000. Annual cost = $90,000.

CIRBY-LINDA-DRY CREEK FLOOD CONTROL PROJECT REPORT AND EIR - In 1989/93 we developed a Conceptual Design Report and an EIR for the Cirby/Linda/Dry Creek Flood Control Project. The project is designed to provide increased levels of flood protection to 262 structures in Roseville. Cost of report and EIR = $1.5 million.

FEMA'S COMMUNITY RATING SYSTEM - By implementing good floodplain management practices, Roseville has become the first and only community in the nation to receive the Federal Emergency Management Agency's (FEMA’s) Community Rating System (CRS) highest rating of Class #1. This rating allows Roseville property owners up to a 45 percent discount on their flood insurance premiums.

The City of Roseville has been actively involved with FEMA’s CRS Program since 1992. This program rates communities on how effective they manage their floodplains. The program rates cities in the following four major categoriess.

1996 - Cirby Creek/I-80 Project (the Tina/Elisa area). This project brought the entire Tina/Elisa neighborhood of 40 homes out of the floodplain. Cost = $3 million (100% City funded).

2001 – Home Elevation Program. FEMA funded 75% of this $1 million program to elevate flood-prone homes. These are structures that would not be brought completely out of the floodplain by construction of our flood control project. Homeowner participation was voluntary. 27 of 44 homeowners on the list elevated their homes via this program. Most of those 27 are located in the Folsom/Maciel neighborhood along Dry Creek.

2001 - Flood control improvements in two areas on Linda Creek: the Champion Oaks/West Colonial Parkway area, and the Sunrise/Oakridge area. This project reduced the size of the floodplain resulting in 233 homes no longer being located in the floodplain, and reducing the risk of flooding for 44 additional homes. Cost = $16.1 million ($8.7 million FEMA funds, $7.4 million City funds).